Imagine playing Frogger on your hand just by tapping your palm with a finger, or whipping through menus projected onto your arm.

Researchers at Carnegie Mellon devised a new bit of tech magic that listed for the acoustic signals scattered through your arm when you tap it or your hand with a finger. The tech can then pinpoint exactly where you touched and translate that into useful input controls for a gadget.

While the clip shows video being transmitted onto someone's arm and hand, including a little game of Frogger, but I suppose you could use permanent additions to your body, like tattoos, to highlight where virtual, tap-sensitive, buttons are located.

The tech, which is in its very early stages, currently uses a bulky cuff, but researchers say it could be the size of a watch eventually. The device could also be built to work with a pico-projector, or perhaps a mobile phone with a built in projector, to cast the image of a screen onto your forearm or hand.

"In the future," researcher Chris Harrison told the BBC, "your hand could be your iPhone and your handset could be watch-sized on your wrist."